Concept [Help] Working around lack of PS_ON pin on 24pin-less boards

[TechCram]

Hi, new here and really just want to get some discussion going on how to deal with this issue

Scenario:
You want to use a standard ATX-based power supply, with the 24pin connector and everything.
But the board you want to use it on doesn't take 24pin
Instead, it takes barrel connectors or straight 12V EPS
Also, it doesn't have a PS_ON pin on board
(edit Also, you want to add a powered riser and a GPU

For example, a SFX power supply with a Thin ITX motherboard, (edit riser and a GTX 1060

The problem is that these boards may not have PS_ON pin that controls the on/off state of the PSU (since it is usually combined into the 24pin connector -- the infamous green wire), which means you can't really tell the mobo to turn on the PSU when you push on the power button (aka close the PWR_ON pin)

You could just short the PS_ON to ground on the PSU side, making the PSU always on. But that's not really a proper solution. (edit Also, adding the GPU now causes a new slew of issues with an always on solution because the GPU will always be receiving power...

So... what do? Are external circuits needed? Or am I missing trick to deal with this?

Thanks

 

[NateDawg72]

While always on may not be the proper solution, it isn't as bad as it sounds

The AC/DC adapters thin ITX & STX boards are designed to take for input are always on if I'm not mistaken. Obviously with a standard ATX power supply you are talking about more power, but I personally think it's okay. Granted, I am biased as I run my PC from a 400w Meanwell PSU that is always on

 

[neilhart]

It would be most helpful if you share the motherboard manufacture and model.

Other wise look for the front panel header, 10-1 pin.

Neil

 

[TechCram]

I updated my original post. I intend to add a powered riser and GPU, so the always on solution gets less enticing.

I plan to work with various boards, and just know that I've come across ones without PS_ON pin. The front panel header will not help, this is a pin normally found in the 24pin ATX connector.

 

[VELKASE Michael]

Find a latching button and wire it to the two wires on the 24 pin connector of the power supply. Those two wires will be shorted and the power supply will be powered on only when the latching button is in the ON state.

 

[el01]

Find a latching button and wire it to the two wires on the 24 pin connector of the power supply. Those two wires will be shorted and the power supply will be powered on only when the latching button is in the ON state.

And perhaps wire the switch to the riser?

 

[NateDawg72]

I don't see the purpose of wiring the switch to the riser if the switch is already turning the PSU on/off

 

[VELKASE Michael]

And perhaps wire the switch to the riser?

Just having a button to power on the PSU will be enough.